Metamath Proof Explorer


Theorem pjpreeq

Description: Equality with a projection. This version of pjeq does not assume the Axiom of Choice via pjhth . (Contributed by Mario Carneiro, 15-May-2014) (New usage is discouraged.)

Ref Expression
Assertion pjpreeq ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ( ( ( proj𝐻 ) ‘ 𝐴 ) = 𝐵 ↔ ( 𝐵𝐻 ∧ ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝐵 + 𝑥 ) ) ) )

Proof

Step Hyp Ref Expression
1 chsh ( 𝐻C𝐻S )
2 shocsh ( 𝐻S → ( ⊥ ‘ 𝐻 ) ∈ S )
3 shsel ( ( 𝐻S ∧ ( ⊥ ‘ 𝐻 ) ∈ S ) → ( 𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ↔ ∃ 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) )
4 1 2 3 syl2anc2 ( 𝐻C → ( 𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ↔ ∃ 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) )
5 4 biimpa ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ∃ 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) )
6 1 2 syl ( 𝐻C → ( ⊥ ‘ 𝐻 ) ∈ S )
7 ocin ( 𝐻S → ( 𝐻 ∩ ( ⊥ ‘ 𝐻 ) ) = 0 )
8 1 7 syl ( 𝐻C → ( 𝐻 ∩ ( ⊥ ‘ 𝐻 ) ) = 0 )
9 pjhthmo ( ( 𝐻S ∧ ( ⊥ ‘ 𝐻 ) ∈ S ∧ ( 𝐻 ∩ ( ⊥ ‘ 𝐻 ) ) = 0 ) → ∃* 𝑦 ( 𝑦𝐻 ∧ ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) )
10 1 6 8 9 syl3anc ( 𝐻C → ∃* 𝑦 ( 𝑦𝐻 ∧ ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) )
11 10 adantr ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ∃* 𝑦 ( 𝑦𝐻 ∧ ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) )
12 reu5 ( ∃! 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ↔ ( ∃ 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ∧ ∃* 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) )
13 df-rmo ( ∃* 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ↔ ∃* 𝑦 ( 𝑦𝐻 ∧ ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) )
14 13 anbi2i ( ( ∃ 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ∧ ∃* 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) ↔ ( ∃ 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ∧ ∃* 𝑦 ( 𝑦𝐻 ∧ ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) ) )
15 12 14 bitri ( ∃! 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ↔ ( ∃ 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ∧ ∃* 𝑦 ( 𝑦𝐻 ∧ ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) ) )
16 5 11 15 sylanbrc ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ∃! 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) )
17 riotacl ( ∃! 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) → ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) ∈ 𝐻 )
18 16 17 syl ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) ∈ 𝐻 )
19 eleq1 ( ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) = 𝐵 → ( ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) ∈ 𝐻𝐵𝐻 ) )
20 18 19 syl5ibcom ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ( ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) = 𝐵𝐵𝐻 ) )
21 20 pm4.71rd ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ( ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) = 𝐵 ↔ ( 𝐵𝐻 ∧ ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) = 𝐵 ) ) )
22 shsss ( ( 𝐻S ∧ ( ⊥ ‘ 𝐻 ) ∈ S ) → ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ⊆ ℋ )
23 1 2 22 syl2anc2 ( 𝐻C → ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ⊆ ℋ )
24 23 sselda ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → 𝐴 ∈ ℋ )
25 pjhval ( ( 𝐻C𝐴 ∈ ℋ ) → ( ( proj𝐻 ) ‘ 𝐴 ) = ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) )
26 24 25 syldan ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ( ( proj𝐻 ) ‘ 𝐴 ) = ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) )
27 26 eqeq1d ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ( ( ( proj𝐻 ) ‘ 𝐴 ) = 𝐵 ↔ ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) = 𝐵 ) )
28 id ( 𝐵𝐻𝐵𝐻 )
29 oveq1 ( 𝑦 = 𝐵 → ( 𝑦 + 𝑥 ) = ( 𝐵 + 𝑥 ) )
30 29 eqeq2d ( 𝑦 = 𝐵 → ( 𝐴 = ( 𝑦 + 𝑥 ) ↔ 𝐴 = ( 𝐵 + 𝑥 ) ) )
31 30 rexbidv ( 𝑦 = 𝐵 → ( ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ↔ ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝐵 + 𝑥 ) ) )
32 31 riota2 ( ( 𝐵𝐻 ∧ ∃! 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) → ( ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝐵 + 𝑥 ) ↔ ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) = 𝐵 ) )
33 28 16 32 syl2anr ( ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) ∧ 𝐵𝐻 ) → ( ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝐵 + 𝑥 ) ↔ ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) = 𝐵 ) )
34 33 pm5.32da ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ( ( 𝐵𝐻 ∧ ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝐵 + 𝑥 ) ) ↔ ( 𝐵𝐻 ∧ ( 𝑦𝐻𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝑦 + 𝑥 ) ) = 𝐵 ) ) )
35 21 27 34 3bitr4d ( ( 𝐻C𝐴 ∈ ( 𝐻 + ( ⊥ ‘ 𝐻 ) ) ) → ( ( ( proj𝐻 ) ‘ 𝐴 ) = 𝐵 ↔ ( 𝐵𝐻 ∧ ∃ 𝑥 ∈ ( ⊥ ‘ 𝐻 ) 𝐴 = ( 𝐵 + 𝑥 ) ) ) )